example-config: Add mail_attachment_detection_options

example-config: Update mail_temp_dir comment

lib-storage: Add mailbox_list_index_include_inbox setting This controls whether to update INBOX's STATUS information in the mailbox list index. It can be useful especially if LISTINDEX points to a tmpfs, but perhaps also in other situations. I considered adding a more generic setting to exclude other mailboxes, but the namespace prefixes and hierarchy separators get a bit complicated with shared mailboxes. It's probably also not very useful to change this for anything but the INBOX.

example-config: Add mailbox_list_index_very_dirty_syncs

example-config: Add mail_sort_max_read_count setting.

example-config: Add mail_vsize_bg_after_count setting.

lib-storage: mailbox_list_index yes by default

lib-storage: mdbox_rotate_size=10M default

example-config: 10-mail.conf: Added example configuration for the new settings relating to IMAP METADATA.

example-config: Added more detailed documentation for mailbox settings.

example-config: Updated mail_attribute_dict comment

Removed support for dnotify. Everybody should be using inotify by now.

example-config: Removed mail_nfs_* settings, since they shouldn't be used anyway.

maildir: Added maildir_empty_new setting to avoid keeping mails in new/ directory. This is useful for example when using an external MDA that calls "doveadm index" and the user hasn't opened the mailbox for a long time. Also this removes the delay that user may see when opening a rarely accessed mailbox, which renames a ton of files to cur/ while the user is waiting.

example-config: Added mailbox_list_index.

example-config: Removed a warning about mail_attachment_dir not being tested.

mail_shared_explicit_inbox: Switched the default from "yes" to "no".

example-config: Added mail_attribute_dict

Added mail_shared_explicit_inbox setting.

mail_temp_scan_interval comment update.

Added mail_temp_scan_interval setting and changed its default from 8h -> 1w.

mbox: Added mbox_md5 setting to select headers for MD5 generation.

example-config: mdbox_rotate_interval default was wrong.

example-config: Use a default uncommented "namespace inbox".

maildir: Added maildir_broken_filename_sizes setting.

Search supports now prefetching data for returned mails. Dropped imapc's own prefetching. mail_prefetch_count specifies how many mails can be kept open and issue a prefetch. This works using posix_fadvise(POSIX_FADV_WILLNEED) for maildir, sdbox and cydir backends. Apparently only Linux supports this. imapc backend also implements this internally by sending wanted IMAP commands to remote server. The command pipelining helps with latency. This change also makes it actually possible for imapc backend to first check if wanted data is already cached in local index and avoid sending unnecessary IMAP commands to remote server.

example-config: Added a warning about mail_attachment* being experimental.

example-config: Added mail_attachment_* settings.

mdbox: Added mdbox_preallocate_space setting to preallocate size for newly created files.

example-config: Added mail_temp_dir.

Renamed fsync_disable to mail_fsync=optimized|always|never. --HG-- branch : HEAD

example-config: Updated global mail_plugins comment. --HG-- branch : HEAD

example-config: Namespace indentation should have been 2 spaces, not 3. --HG-- branch : HEAD

example-config: Example namespace's hidden value default was wrong. --HG-- branch : HEAD

example-config: mdbox_altmove setting no longer exists, removed it. --HG-- branch : HEAD

example-config: Removed some old comments that aren't really useful anymore. --HG-- branch : HEAD

example-config: Added nn- prefix to *.conf files so the sort ordering makes more sense. This is especially important to get mail_plugins = $mail_plugins example working in protocol sections. --HG-- branch : HEAD